Systematics, character evolution, and biogeography of Cistus L. (Cistaceae) based on ITS, trnL-trnF, and matK sequences

This paper presents the first phylogenctic hypotheses for the 20 species of Cistus based on plastid (trnL-trnF, matK) and nuclear (ITS) DNA sequence data. Phylogenetic relationships reveal that: (1) Halimium and Cistus form a cohesive, natural group; (2) two major lineages of purple-flowered and white-flowered species are defined, except for the purple-flowered C parviflorus; (3) monophyly of conspecific populations is congruent with the Circumscription of species. Topological congruence between nuclear and plastid phylogenies does not Support a predominant reticulate system of evolution in Cistus. Reconstruction of character evolution Suggests all increment of number of fruit valves in the Cistaceae from 3 to 12 in a unidirectional manner. In contrast, reproductive characters, such as sepal number, petal color, and style length, evolved multiple times in the Course of evolution. A single colonization of Cistus into the Canary Islands appears to be responsible for a lineage Of four species sharing a, purple flowers, styles as long as stamens. and five fruit valves. Species diversity in most recent common ancestor with five sepals. Cistus (14) and Halimium (8), coupled With sister-group relationships and molecular divergence, lead us to suggest the western Mediterranean as a major center of present-day differentiation, but paleobotanical data indicate an earlier formation of the Cistus-Halimium assemblage in different areas. (c) 2005 Elsevier Inc. All rights reserved.